Hi Anupam,
You can study AP of Class 10th from here http://teachoo.com/subjects/cbse-maths/class-10th/ch5-10th-arithmetic-progressions/
and of Class 11 from https://www.teachoo.com/subjects/cbse-maths/class-11th/ch9-11th-sequences-and-series/
Written on Feb. 16, 2017, 10:21 p.m.